Apparatus for marking objects



May 2, 1933. A. c. CHRESTOPHERSON 1,996,875

APPARATUS FOR MARKING OBJECTS Filed July 26, 1928 3 Sheets-Sheet l M y 2, 1933. A. c. CHRISTOPHERSON 1,905,876

APPARATUS FOR MARKING OBJECTS Filed July 26, 1928 5 Sheets-Sheet 2 y 2, 1933- A. c. CHRISTOPHERSON 7 APPARATUS FOR MARKING OBJECTS Filed July 26, 1928 3 Sheets-Sheet 3 LLL Patented May 2, 1933 ALFRED C. CHBISTOPHERSON, OF CHICAGO, ILLINOIS, ASSIGNOB TO HACKER MANU- FACTURING 00., OF CHICAGO, ILLINOIS, A COBPORATIGN O1 ILLINOIS APPARATUS FOR MARKING OBJECTS Application filed July 28, 1928.

My invention relates to an apparatus for marking objects and is very usefully employed in providing a series of color printing plates with equally spaced mar s in '1 order that the plates may be successively impins provided upon the printing beds. These positioning pins were insutlicient to hold the plates down upon the beds, it having been necessary to employ so-called register hooks that served this purpose. It is one object of my invention to provide an apparatus which renders the use of the positioning pins needless, the plate being so formed, in accordance with my invention, that some of the register hooks will serve as positioning means as well as plate holding means, being allowed to remain in a fixed position for the imposition of all of the printing plates of a series. The invention, however, is not to be thus limited.

In carrying out-my invention, I employ a trimming tool preferably a saw which trims the edges of the plates of a series to exact size and means for so relatively positioning the saw and the plates successively trimmed 1 thereby that the edges of the plates will be accurately located with respect to the engravings upon the plates so that if the register hooks engaging the two adjacent sides of the first imposed plates of a series are allowed to remain in fixed position for engagement with all of the plates of the series, the succeeding plates that are imposed with the aid of these particular register hooks will be in exactly correct printing position and without the aid of any special positioning pins as were hitherto required. The saw is thus a plate marking tool and the trimmed edges are positioning marks made by the saw on the plates.

Apparatus constructed in accordance with Serial No. 295,352.

the preferred embodiment of the invention is inclusive of a bed for supporting the plates that are to be trimmed, a gauge spaced above the bed to permit the positioning of the plates to be trimmed beneath the gauge and over the bed, and having indices located at a distance from each other for register with correspondingly spaced apart indices upon the plates that are to be trimmed, and a saw or other trimming tool in such relation with either or both the bed and gauge as to be enabled to trim the plates to bring at least two adjacent edges thereof in exactly the right relation to the indices upon the plates. In the preferred embodiment of the invention, the apparatus is adapted to trim all of the edges of the plates to bring them in exact relation to the indices upon the plates so that any collection of register hooks may be selected for permanent location to position all of the plates of a series successively. The

indices upon the plates may be specially photographed marks which are not to appear in the prints or they may be similar parts of the engravings that appear upon all of the plates. For example, if the plates are engraved for the printing of the picture of abird in colors, the head and tail, if appcaring upon all of the plates, could be selected as the similarly positioned indices common to all of the plates of the series.

The gauge which I employ is preferably one which is inclusive of coplanar and preforab-ly transparent portions which are located at a distance from each other and are movable transversely of and with respect to the bed to receive imprints from spaced apart portions of a printing plate on the bed to provide indices on the gauge that are located at a distance from each other for re ister with corresponding printing plate portionsupon each plate to be marked. The imprints upon the transparent portions of the gauge are taken from the first of a series of plates in which series all of the plates have similar printing portions so that each plate of the series may be properly positioned wi h respect to the gauge to enable it to be accurately marked so that it may accurately replace each previously used plate with relation to the marking elements or guides and the gauge. This is another feature of my invention.

The invention will be more fully explained in connection with the accompanying drawings in which Fig. 1 is a plan View illustrating the preferred embodiment of the invention with a portion of the gauge broken away; Fig. 2 is a sectional view on line 22 of Fig. 1; Fig. 3 is a sectional view on line 3-3 of Fig. 1; Fig. 4 is a side view partly in section; and Fig. 5 is a perspective view, detailing the gauge and one of the printing plates which is to be positioned with the aid of the gauge for the trimming operation.

The portion of the apparatus which serves to trim the plates and to position them for trimming may be first described whereafter the gauge may be described in its relation to the balance of the apparatus. A circular saw 1 is illustrated, this saw being carried upon a shaft 2 which may be driven by an electric motor 3. The saw and motor for driving it are provided upon a carriage l which is equipped with a handle 5 whereby the carriage may be moved back and forth upon the bed 6 of the machine, this bed being inclusive of a guide 7 having a groove which receives the V shaped rib 8 of the carriage, the groove being parallel with the plane of rotation of the saw whereby the carriage is limited to a line of travel which is parallel with the plane of rotation of the saw or in which such line of travel is abreast of such plane of rotation, the invention not being limited to exact parallelism between the plane of rotation of the saw and the line or path in which the saw is bodily moved.

A work holding bed 9 is shown as being rectangular in contour and as having an underlying circular enlargement 10 which is coaxial with the shaft 11 that is carried by and projects beneath the table and is journaled within an upright bearing 12 which is formed upon the bed 13, the beds 6 and 13 being desirably integrally formed in one casting. A nut 14 is screwed upon the lower end of the shaft 11 and engages the bottom face of the upright bearing 12 whereby the work holding bed is held in one plane whether it is in motion or at rest. A tapered pin 15 is passed through a tapering hole in the flange 16 of the bed 13 and into either of the two tapering holes 17 and 18 formed in the H work holding bed, the holes 17 and 18 being,

in the embodiment of the invention illustrated, equidistant from the axis of the shaft 11 and upon lines that radiate from the axis of said shaft at right angles to each other.

These radiating lines that pass through the centers of the holes 17 and 18 are respective ly perpendicular to adjacent sides of the rectangular work holding bed. One of these two lines is parallel with the guide 7 and the other is perpendicular to this guide.

The plate 19 to be trimmed is suitably held by means of clamps, to be described. WVhen the pin 15 is in the hole 17 and the carriage 4 for the saw is moved in the guide 7, one side of said plate is trimmed. Then the pin 15 is withdrawn from the hole 17 and the work holding bed is turned to enable said pin to be received in the hole 18, a side of the plate 19 adjacent that which was previously trimmed may itself be trimmed in a similar manner with the result that these two plate sides are in exact right angular relationship whereafter the remaining two plate sides may be similarly trimmed to have them in exact right angular relationship.

The means for holding the plate 19 upon the work holding bed is desirably inclusive of any two clamping devices of similar construction, a description of one being applicable to both. Each clamping device iilustrated includes an arm 20 which is pivoted, at one end, upon a pivot bolt 21 which is carried by a bracket 22 that projects upward- 1y from the work holding bed. A number of spaced apart rods 23 pass through and are slidable within sleeves 24 that are integrally formed with said arms, there being nuts 25 upon the upper ends of said rods to limit the extent to which the rods may be lowered. Enlargements 26 are provided upon the lower ends of the rods 23, there being coiled springs 27 around the rods 23v and between these enlargements and the arm which carries said rods. Presser feet 28 are universally joined with and within the bottoms of the enlargements 26 so that when the arm 20 is lowered, the bottom faces of these presser feet may be in full engagement with the top of the printing plate. A cam disc 29 is eccentrically mounted upon a shaft 30, this shaft being carried in the upper end of a bracket 31 which is carried by and projects upwardly from the work holding bed. A circular hole 32 is provided in the arm 20 which is coaxial with the shaft 30. The hole 32 receives the disc 29 which engages the rim of the hole 32 at one point and is clear of it elsewhere. A handle 33 is secured to the shaft 30. When the arm has been lowered to a position in which the presser feet engage the printing plate 28, the cam 29 is in engagement with an upper portion of the rim 01 the hole 32 so that the contact between the presser feet and the printing plate is initially light. Said plate is then firmly bound upon the work holding bed by turning the disc 29 to bring its point of greatest eccentricity below the shaft 30 so as to force said arm to its lowermost position in which the presser feet will be held in firm engagement with the the handle, 33 is restored to the position first described to elevate the arm 20, such elevation being assisted by the spring 34 which is carried by the work holding bed and presses upwardly against the bottom of the arm. The edges of printing plates are beveled so that they may be engaged by a register hook or plate holding clamp that is adjustably assembled with the printing bed that carries the plate. To this end, the carriage 4 is so shaped as to cause the plane of the saw 1 to be oblique to the work holding top face of the work holding bed as is shown most clearly in Fig. 2, the arrangement being such that the. edge of the printing plate 19 is properly presented to the teeth of the saw as the saw is bodily moved along the edge of the print ing plate that is being trimmed.

A sheet of celluloid or other transparent material 35, employed in the preferred form of gauge, is mounted upon a square shaft 36. This shaft has tapered ends which are respectively received within an upright tapered groove in the unitary block 37 that is secured upon the table in an upright tapered groove provided in the adjacent sides of two upright blocks 38 and 39 that are also carried by the work holding bed, the block 39 being directly screwed upon said work holding bed while the block 38 is maintained in assembly with the block 39 by means of the bolt 40 which is carried by the block 39 and passes throngl'i the block 38, said bolt and this latter block being in snug sliding relation. A coiled spring 41 presses the block 38 toward the block 39 and serves to press the block 38 upon the adjacent tapered end of the shaft 36 in a manner to force the other tapered end of this shaft in snug engagement with the upright groove in the block 37.

A handle 42 is provided upon the shaft 36 in order that the sheet of transparent material 35 may be swung up or down. The shaft 36 is disposed closely enough to the work holding bed and said transparent sheet is so disposed upon the shaft, that the sheet may be lowered to a horizontal position sufficient ly close to the work holding bed to lie fiat upon the printing plate 19 that is positioned upon the work holding bed to enable the gauge sheet 35 to lie thereover and thereon. The spaced apart indi-ces that are to be provided upon the gauge sheet are desirably produced by imprints taken fro-1n spaced apart portions, such as indicated at 43 and 44, of the first plate of a series which is placed upon the machine tobe trimmed and which portions 43 and 44 are repeated upon all of the other plates. The imprints of the portions 43 and 44, of the first printing plate, that appear upon the gauge sheet 35 are indicated at 43, 44, these imprints 43, 44 constituting spaced apart indices that are upon coplanar portions of the gauge sheet 35. The engraving portions 43, 44 and the imprints 43, 44' thereof happen to be the head and tail of the picture of a bird. The balance of the picture of the bird is indicated in Figs. 1 and 5 by dotand dash lines.

The first plate of the series is positioned with ordinary care with respect to the work holding bed and the guide 7 for the trimming saw or tool. The first plate to be trimmed has two of its adjacent edges operated upon by the saw by suitably turning the work holding bed, as is understood from the previous description whereby these twoedge portions are brought into exact right angular relation in order that they may cooperate With the temporarily fixed register hooks or plate clamps that are provided upon the printing bed whereby this plate may be accurately positioned in the printing operation. Each succeeding plate of a series thereafter has two of its adjacent edge portions trimmed in a similar manner after it has been positioned with parts 43 and 44 in register with the imprints 43, 44 upon the gauge sheet 35, this gauge sheet being lowered upon each succeeding plate to bring its parts 43, 44 into register with the parts 43, 44. After each plate of a series has two of its edges thus trimmed, the remaining two edges thereof may be trimmed in a similar manner in conjunction with other gauge marks imprinted upon the gauge sheet 35 or the partially trimmed plates may be otherwise positioned in order that the remaining edges may be trimmed. Reliance, however, may be had upon the two edges of each plate that are first trimmed for the accurate location of the plates in succession upon the printing bed in which event the accuracy of the location of the remaining two edges of each printing plate is not so important. The gauge sheet may have two of its adjacent edges recessed or serrated as illustrated in Fig. 5 to provide spaces in which the presser feet 28 may be received so that it will not be necessary to raise the gauge sheet until the saw has made its cut. VVhilo the saw or other trimming tool desirably trims each side of the plate throughout the extent of such plate side, it is obvious that the plate need be only sufficiently trimmed to properly receive the register hooks or plate clamps employed in holding the plate for printing and all of the portions of the plate sides between the adjacent plate clamps need not be adapted for engagement by such clamps.

It will be seen that my invention is of importance not only in effecting the proper relationship between printing plate sides but also in enabling the elimination of special grooves in printing plate beds and the. positioning pin bearing blocks that are slidable in these grooves. The elimination of these grooves and the blocks therein greatly simplifies the construction of printing plate beds as will be appreciated by those familiar with the art. Thus, no addition to the equipment or expensive modification are required in connection with printing apparatus employing register hooks for clamping printing plates as employed in single color printing.

When it is stated in the claims that a fixed relation exists between certain elements of the implement it is intended to mean that such fixed relation is only necessarily constant during the marking of one set of plates essential to the production of a single design; and such definition of structure is intended to include within its scope implements of this character wherein elements are relatively adjustable so that one fixed relation may be provided therebetween to mark one set of plates and another fixed relation provided, it necessary, to mark another set of plates.

While I have herein shown and particularly described the preferred structure of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention, I claim as new and desire to secure by Letters Patent the following:

1. Apparatus for trimming printing plates including a bed for supporting the plate; a transparent gauge sheet swingable upon said bed to overlie the bed, said. gauge sheet being fixed on an axis in a given plane relatively to the bed but said axis being movable vertically in said plane to space the gauge sheet from the bed to lie parallel and in contact with the plat spaced apartdefining indices upon the gauge for register with corresponding indices upon the plate; means for fixing the relation of the plate with respect to the bed; and means for trimming adjacent edges of said plate in planes respectively parallel and perpendicular to the axis of the gauge sheet. said trimming means including a circular saw tilted to cut a beveled edge on the plate and said saw and bed being relatively movable to trim said adjacent edges.

2. Apparatus for trimming printing plates including a bed for supporting a plate with adjacent edges of the plate overhanging the bed: a transparent gauge sheet swingable upon said bed on an axis in a plane xed with respect to the bed to overlie said plate. said sheet being discontinued in the region of said overhanging edges: area defining indices on said sheet; means free from the gauge sheet for fixing the relation of the plate with respect to the bed: and means including a circular saw rotatable and movable relatively to the bed in a plane passing through one of said overhanging edges to cut a beveled edge on the plate.

3. Apparatus for trimming printing plates including a rotatable bed for supporting a plate with adjacent edges of the plate overhanging the bed; a transparent gauge sheet s "ingable upon said bed to overlie the bed, said gauge sheet being fixed on an axis in a fixed plane relatively to the bed but said axis being movable vertically in said plane to space the gauge sheet from the bed to lie parallel and in contact with the plate; spaced apart area defining indices upon the gauge for register with corresponding indices upon the plate; clamps for fixing the relation of the plate with respect to the bed, said gauge sheet being discontinued in the region of said clamps and said overhanging edges; a rotatable tilted circular trimming saw movable along the edge of the plate in a plane passing through the portion of the plate overhanging the bed, said saw cutting a beveled edge successively on two adjacent edges or" the plate is the saw is moved first along one edge and then the bed is rotated to a position perpendicularly to its first position to present the adjacent edge of the plate to the v and the saw moved along said latter edge; and means for fixing the bed in said two respective rotative positions.

In witness whereof, I hereunto subscribe my name.

ALFRlT) C. CHRISTOPHERSON. 

